docs: Add toJSON function to supported ClickHouse functions

contents/docs/data-warehouse/sql/data-access.mdx

@@ -38,7 +38,7 @@ SELECT round(properties.$screen_width * properties.$screen_height / 1000000, 2)
 
 This works because `$screen_width` and `$screen_height` are both defined as numeric properties. Thus you can multiply them.
 
-To cast a string property into a different type, use type conversion functions, such as`toString`, `toDate`, `toFloat`, `JSONExtractString`, `JSONExtractInt`, and more.
+To cast a string property into a different type, use type conversion functions, such as `toString`, `toDate`, `toFloat`, `toJSON`, `JSONExtractString`, `JSONExtractInt`, and more.
 
 ## Property access
 

contents/docs/data-warehouse/sql/useful-functions.mdx

@@ -92,6 +92,13 @@ select properties.$set.$geoip_country_name
 from events
 ```
 
+To convert a string property to the JSON type (useful for views where properties are stored as strings), use `toJSON()`:
+
+```sql
+SELECT toJSON(properties).some_field
+FROM events
+```
+
 You can parse JSON with `JSONExtractRaw()` to return a value.
 
 ```sql

contents/docs/sql/clickhouse-functions.mdx

@@ -142,6 +142,7 @@ If the function's name includes a leading underscore, then it's not safe and sim
 - `toUUID`
 - `toString`
 - `toBool`
+- `toJSON`
 - `toJSONString`
 - `toTypeName`
 - `parseDateTime`